FEL wont stay up

[stan33]

Yep. Standard DA cylinder.

With no air trapped and no external leaks, if that cylinder is retracting under just the weight of gravity, the valve is the issue

And that's without the bucket. With the bucket (which is incredibly heavy...very thick steel) and a load in the bucket I am thinking I may have probs if I dont get this sorted.

 

[Tx Jim]

Yep. Standard DA cylinder.

With no air trapped and no external leaks, if that cylinder is retracting under just the weight of gravity, the valve is the issue

LD1
Thanks for agreeing with me.
Jim

 

[Tx Jim]

And that's without the bucket. With the bucket (which is incredibly heavy...very thick steel) and a load in the bucket I am thinking I may have probs if I dont get this sorted.

Stan33
You can prove to yourself that cyl piston packings aren't the problem by raising loader boom up then CAREFULLY remove hyd hoses on both sides from fitting closest to big nut on rod end of cylinder. If packings are at fault as some believe a sufficient amount oil should exit hyd fitting attached to cylinder barrel as boom lowers. When no oil exits these fittings then this will prove that control valve is at fault for boom settling..

 

[stan33]

Stan33
You can prove to yourself that cyl piston packings aren't the problem by raising loader boom up then CAREFULLY remove hyd hoses on both sides from fitting closest to big nut on rod end of cylinder. If packings are at fault as some believe a sufficient amount oil should exit hyd fitting attached to cylinder barrel as boom lowers. When no oil exits these fittings then this will prove that control valve is at fault for boom settling..

I think I might try the old hose switcheroo first (sounds less scary). It may fix the problem there and then, cos that other valve has probably always just operated the single bucket ram and could be in much better condition.
And maybe the worn one can work the bucket without droop.
Thanks guys for all your help, much appreciated. Will let you know how I get on.

 

[LD1]

LD1
Thanks for agreeing with me.
Jim

This is only about the 12th time we have been down this road in the last few years.

For whatever reason, simple hydraulic principals are just hard for some to understand.

Stan33
You can prove to yourself that cyl piston packings aren't the problem by raising loader boom up then CAREFULLY remove hyd hoses on both sides from fitting closest to big nut on rod end of cylinder. If packings are at fault as some believe a sufficient amount oil should exit hyd fitting attached to cylinder barrel as boom lowers. When no oil exits these fittings then this will prove that control valve is at fault for boom settling..

That could prove packing is not the issue, but it can also prove nothing.

The piston seals may very well be shot. And removing the rod hose will cause all kinds of fluid to pour out and the loader to drop. Or they could be good and only a drip will come out. Good test for the seals, but does little to prove the valve is bad IMO.

A really good test, raise the loader up a few feet and put a jack under it. Take the hoses off at the valve (so you dont loose all the fluid out of the cylinders) and plug them. The remove the jack. You can come back in a year and the loader will still be the same height provided you dont have any external leaks.

 

[Tx Jim]

This is only about the 12th time we have been down this road in the last few years.

For whatever reason, simple hydraulic principals are just hard for some to understand.

The piston seals may very well be shot. And removing the rod hose will cause all kinds of fluid to pour out and the loader to drop.

LD1
The simple answer to your statement is "some folks have a very difficult time admitting when they make a wrong statement or have a wrong idea".

2nd I seriously doubt Stan's cyl packings are bad enough for a lot of hyd oil to pour out but your "test idea" is safer/cleaner.

Jim

 

[J_J]

But just because a packing seal is leaking on a cylinder does not indicate that fluid has a place to go. If suction hose was leaking and pump was sucking air would not hyd oil be FOAMY????????????

Sure it would, and over night or over time, the tiny air bubbles in the hoses and valves would regroup in a bubble.

The bubbles in the reservoir would dissipate.

 

[stan33]

Just went to put the boom down fully. The boom ends were now about 3ft off the ground. I let the boom down a few inches and returned the valve to neutral.
From this position and with the valve in neutral, the boom continued to the ground by itself without stopping. This was with the engine off. With the engine on, it does not do this with the boom in a lowish position.

 

[J_J]

Some of you are so hard headed, and set in your ways, and stuck in your beliefs that you fail to find/research what is right/correct.

If you don't believe that a cyl will descend with bad seals, then place your head under the bucket and see if your faith is secure.

This excerpt is from Prince and tells how to determine cyl seal leakage.

Place a load in the bucket that induces a pressure reading in the boom cylinder base end of approximately 1000 psi. Raise to approximately mid-stroke. After a short period of time note the pressure on the rod end side of the boom cylinders. It should be near zero and not increasing. If it is not near zero or is increasing, oil is leaking past one or both of the boom cylinder piston seals and the cylinders need to be repaired or replaced.

Prince Hydraulics > Support > Loader Valve FAQ

I could forgive you all for calling me a liar, but I want.

 

[J_J]

You really want to test the valves spools, then get a manual hyd pump and connect it to one of the work ports, and pump up enough pressure to satisfy yourself.

Do a similar test to a cyl to check seals.